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When to Plant Bachelor's Button in Curry County, OR

Curry County, Oregon Zone 9b July

Your July gardening checklist

Each item below is timed to Curry County, Oregon's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 21
Avg. first frost November 21
Soil temp (4") 93°F
Watering Critical
Pest pressure High
Daylight 14.8 hrs

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Bachelor's Button (Centaurea cyanus), also called cornflower, is a carefree cool-season annual best known for its vivid cobalt-blue flowers — one of the truest blues in the annual garden. It tolerates light frosts, self-seeds prolifically, and thrives in poor to average soils. A traditional cut flower and pollinator magnet, it has been cultivated in gardens for centuries.

Curry County, Oregon is in USDA Zone 9b. The average last spring frost is March 21 and the first fall frost is November 21, giving you a growing season of approximately 245 days.

At an elevation of 295 feet, Curry County receives approximately 53.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Bachelor's Button during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Bachelor's Button root diseases.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Curry County, OR (Zone 9b) Long season
245 days
Last Spring Frost March 21
245 growing days
First Fall Frost November 21

Curry County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.7

Drainage

Well Drained

Bachelor's Button Planting Risk Windows

Early Start (70% safe) ✓ Fits season (107 days to spare)
Transplant: Jan 24 🌸 Bloom: Mar 21 – Jul 11
Recommended (50%) ✓ Fits season (112 days to spare)
Transplant: Feb 14 🌸 Bloom: Apr 11 – Aug 1
Safe Start (90%) ✓ Fits season (93 days to spare)
Transplant: Apr 1 🌸 Bloom: May 27 – Sep 16

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Curry County

How your county's soil matches Bachelor's Button's growing requirements.

Soil pH

Your soil pH (5.7–6.7) overlaps with Bachelor's Button's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Curry County is excellent for Bachelor's Button — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.4%) — Bachelor's Button will thrive.

How to Plant Bachelor's Button

0.3"
Planting Depth
12"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Bachelor's Button

4
successive plantings in your 245-day season

Sow every 6.9 weeks. Last sowing by Aug 23 to harvest before frost.

For a dedicated fall crop, sow by Sep 12.

Bachelor's Button Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Bachelor's Button

Bachelor's Button needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Bachelor's Button Needs Rainfall You Supplement Action
Jan 8.2" 0" ❄️ Dormant
Feb 5.6" 0" ❄️ Dormant
Mar 2.2" 5.5" 0" ✅ Rainfall sufficient
Apr 2.2" 4.1" 0" ✅ Rainfall sufficient
May 2.2" 3.4" 0" ✅ Rainfall sufficient
Jun 2.2" 2.1" 0.1" 💧 Light watering
Jul 2.2" 0.8" 1.4" 🚿 Regular watering
Aug 2.2" 0.9" 1.3" 🚿 Regular watering
Sep 2.2" 2" 0.2" 💧 Light watering
Oct 2.2" 4.6" 0" ✅ Rainfall sufficient
Nov 2.2" 8.1" 0" ✅ Rainfall sufficient
Dec 7.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Curry County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Bachelor's Button Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Bachelor's Button needs ~1,425 GDD — county provides 4,655 GDD Excellent fit

Bachelor's Button Planting Timeline — Curry County, OR

Bachelor's Button Planting Calendar

Activity When Date Range
Transplant Outdoors February 14 Feb 14 – Feb 28
Direct Sow January 17 Jan 17 – Feb 7
Bloom April 11 Apr 11 – Aug 1
Fall Sowing September 12 Sep 12 – Sep 26

Plant 0.3" deep · 12" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Direct Sow
February Transplant Outdoors Direct Sow
March
April Bloom
May Bloom
June Bloom
July Bloom
August Bloom
September Fall Sowing
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

245 days in Curry County

Growing Tips for Bachelor's Button in Curry County

Direct sow Bachelor's Button outdoors after March 21 in Curry County when soil has warmed and frost danger has passed.

Common pests for Bachelor's Button in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct-sow in early spring as soon as soil can be worked; seeds need a brief cold period for best germination (refrigerate for a few days before planting if spring arrives quickly). In zones 6+, fall-sow for the earliest spring bloom. Thin to 12 inches; do not over-fertilize — too much nitrogen produces foliage at the expense of flowers. Deadhead to prolong blooming or allow self-seeding for a naturalized colony.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Bachelor's Button in Curry County, OR?

Curry County is in Zone 9b with an average last frost of March 21. Plan your Bachelor's Button planting based on this frost date — see the calendar above for exact timing.

What planting zone is Curry County, OR?

Curry County, Oregon is in USDA Hardiness Zone 9b. The average last spring frost is March 21 and first fall frost is November 21.

🌱

Your Curry County Garden Planner — Free

A 22-page printable planner built for Curry County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Curry County, OR. Local conditions may vary. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.